Dietary water balance in a tropical insect
Dietary water intake of the tropical grasshopperPoecilocerus pictus fedad libitum from hatching to death on the milkweedCalotropis gigantea averaged 85 or 51 g at 26°C and 171 or 78 g at 36°C for a female and male respectively. As much as 54 or 96 g dietary water is lost via faeces by a female at 26 or 36°C; the corresponding values for a male was 37.5 and 36.2 g. A male or female carried at death about 9 or 6% of the respective dietary water absorbed at 26 or 36.°C. Water loss via exuvia amounted to 26 mg in all the series. Due to oviposition 4.8 or 7.4% of the total water absorbed was lost by a female at 26 or 36°C. There exist a very close relationship between the efficiencies of matter assimilation and water absorption. The high dietary water intake and absorption rates reported for the tropical lepidopteranDanaus chrysippus are correlated with the accumulation of water to meet the requirements during the nonfeeding pupal stage.